CVE-2026-2836: https://github.com/cloudflare/pingora · CWE-345
Affects https://github.com/cloudflare/pingoraSource CVE Database V5
Not known to be exploited · CVSS 8.4 High : upgrade to 0.8.0 soon.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.8.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 4 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade https://github.com/cloudflare/pingora to 0.8.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Cloudflarehttps://github.com/cloudflare/pingora | Affected
| Fixed in
|
GitHubcloudflare/pingorapkg:github/cloudflare/pingoraOther threats | Affected
| Fixed in– |
GitHubhttps://github.com/cloudflare/pingorapkg:github/https://github.com/cloudflare/pingoraOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
- Upgrade immediately to Pingora version 0.8.0 or later, which removes the insecure default cache key implementation.
- Implement explicit cache key callbacks that incorporate the Host header (authority), upstream HTTP scheme, and any other relevant request attributes to ensure cache keys uniquely identify cached content per tenant or origin.
- For users on older versions unable to upgrade immediately, remove any usage of the default CacheKey implementation and replace it with a custom cache key function that includes at minimum the Host header and upstream peer’s HTTP scheme.
- Conduct thorough testing of cache behavior post-implementation to verify that cross-tenant cache poisoning is mitigated and that cache keys correctly segregate tenant data.
- Monitor proxy logs for unusual cache hit patterns or anomalies that could indicate attempted cache poisoning.
- Educate development and operations teams about the risks of default cache key usage and the importance of customizing cache keys in multi-tenant environments.
- Review and audit other proxy or caching components in the infrastructure for similar cache key construction issues to prevent analogous vulnerabilities.
Description
A cache poisoning vulnerability has been found in the Pingora HTTP proxy framework’s default cache key construction. The issue occurs because the default HTTP cache key implementation generates cache keys using only the URI path, excluding critical factors such as the host header (authority). Operators relying on the default are vulnerable to cache poisoning, and cross-origin responses may be improperly served to users. Impact This vulnerability affects users of Pingora's alpha proxy caching feature who relied on the default CacheKey implementation. An attacker could exploit this for: * Cross-tenant data leakage: In multi-tenant deployments, poison the cache so that users from one tenant receive cached responses from another tenant * Cache poisoning attacks: Serve malicious content to legitimate users by poisoning shared cache entries Cloudflare's CDN infrastructure was not affected by this vulnerability, as Cloudflare's default cache key implementation uses multiple factors to prevent cache key poisoning and never made use of the previously provided default. Mitigation: We strongly recommend Pingora users to upgrade to Pingora v0.8.0 or higher, which removes the insecure default cache key implementation. Users must now explicitly implement their own callback that includes appropriate factors such as Host header, origin server HTTP scheme, and other attributes their cache should vary on. Pingora users on previous versions may also remove any of their default CacheKey usage and implement their own that should at minimum include the host header / authority and upstream peer’s HTTP scheme.